507 research outputs found

    An international, multicentre evaluation and description of Burkholderia pseudomallei infection in cystic fibrosis

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    BACKGROUND: Several cases of Burkholderia pseudomallei infection in CF have been previously reported. We aimed to identify all cases globally, risk factors for acquisition, clinical consequences, and optimal treatment strategies. METHODS: We performed a literature search to identify all published cases of B. pseudomallei infection in CF. In addition we hand-searched respiratory journals, and contacted experts in infectious diseases and CF around the world. Supervising clinicians for identified cases were contacted and contemporaneous clinical data was requested. RESULTS: 25 culture-confirmed cases were identified. The median age at acquisition was 21 years, mean FEV(1) % predicted was 60 %, and mean BMI was 19.5 kg/m(2). The location of acquisition was northern Australia or south-east Asia for most. 19 patients (76 %) developed chronic infection, which was usually associated with clinical decline. Successful eradication strategies included a minimum of two weeks of intravenous ceftazidime, followed by a consolidation phase with trimethoprim/sulfamethoxazole, and this resulted in a higher chance of success when instituted early. Three cases of lung transplantation have been recorded in the setting of chronic B. pseudomallei infection. CONCLUSION: Chronic carriage of B. pseudomallei in patients with CF appears common after infection, in contrast to the non-CF population. This is often associated with an accelerated clinical decline. Lung transplantation has been performed in select cases of chronic B. pseudomallei infection. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12890-015-0109-9) contains supplementary material, which is available to authorized users

    Theory of Dispersed Fixed-Delay Interferometry for Radial Velocity Exoplanet Searches

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    The dispersed fixed-delay interferometer (DFDI) represents a new instrument concept for high-precision radial velocity (RV) surveys for extrasolar planets. A combination of Michelson interferometer and medium-resolution spectrograph, it has the potential for performing multi-object surveys, where most previous RV techniques have been limited to observing only one target at a time. Because of the large sample of extrasolar planets needed to better understand planetary formation, evolution, and prevalence, this new technique represents a logical next step in instrumentation for RV extrasolar planet searches, and has been proven with the single-object Exoplanet Tracker (ET) at Kitt Peak National Observatory, and the multi-object W. M. Keck/MARVELS Exoplanet Tracker at Apache Point Observatory. The development of the ET instruments has necessitated fleshing out a detailed understanding of the physical principles of the DFDI technique. Here we summarize the fundamental theoretical material needed to understand the technique and provide an overview of the physics underlying the instrument's working. We also derive some useful analytical formulae that can be used to estimate the level of various sources of error generic to the technique, such as photon shot noise when using a fiducial reference spectrum, contamination by secondary spectra (e.g., crowded sources, spectroscopic binaries, or moonlight contamination), residual interferometer comb, and reference cross-talk error. Following this, we show that the use of a traditional gas absorption fiducial reference with a DFDI can incur significant systematic errors that must be taken into account at the precision levels required to detect extrasolar planets.Comment: 58 pages, 11 figures, 1 table, 3 appendices. Accepted for publication in ApJS. Minor typographical corrections; update to acknowledgment

    Effective CCTV and the challenge of constructing legitimate suspicion using remote visual images

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    This paper compares the effectiveness of public CCTV systems according to meta-reviews, with what might be expected based upon theoretical predictions. The apparent gulf between practice and prediction is explored in the light of the challenges faced by CCTV operators in terms of effective target selection. In addition, counter-intuitive reactions by members of the public to situational symbols of crime deterrence may also undermine the efficacy of CCTV. Evidence is introduced and reviewed that suggests CCTV operators may employ implicit profiles to select targets. Essentially, young, scruffy males who appear to be loitering are disproportionately targeted compared with their base rate use of surveyed areas. However, the extent to which such a profile is diagnostic of criminal intent or behaviour is unclear. Such profiles may represent little more than ‘pattern matching’ within an impoverished visual medium. Finally, suggestions for future research and effective CCTV operator practice are offered in order to improve target selection.Peer reviewe

    An Analysis of the Adequacy of Preparation for the Totality of Worship Leadership

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    Despite the gradual transition of “music minister” into “worship leader,” preparation and training for the expanded roles may be considered slow in terms of total responsibilities. While degree programs have incorporated in-depth coursework in essential ministry topics – such as theology, discipleship, and evangelism – there has been little recognition of their roles as managers and counselors. Many of these programs prepare students for jobs that no longer exist. This study focuses on the worship leader, both as a student and as one who has already started their career, with responsibilities in the church and to their family. Through qualitative historical research, this study examines some of the academic programs that address initial worship leader training. It specifically examines worship studies and sacred music programs to identify specific modifications needed to prepare for worship leader positions as they are currently constituted. Additionally, this study provides a suggested curriculum for comprehensive worship leader training; worship leaders who have already begun their careers can use this curriculum to identify the training they may be missing. To determine these needs, this study compares the worship leader roles identified in earlier studies with the publicly available descriptions of academic programs currently offered for worship leader education. This training prepares the worship leader for the entirety of their current ministry, as well as the possibility of transitioning to another area of ministry should circumstances dictate

    Magnetic variation anomalies in northern England and southern Scotland

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    Single-station transfer functions linking the time variations of the vertical and horizontal components of the magnetic field at stations in northern England and southern Scotland have been compiled into a uniform data set. From hypothetical event analysis we show here that there are two distinct anomalies in the Borders region. One runs south-west to north-east, immediately to the south-east of the Southern Uplands Fault; the second follows the Northumberland Basin, and seems to exist because the conductive sedimentary rocks filling the basin create a link between the Irish and North Seas. If the Iapetus suture is marked by a conductivity anomaly, as has been suggested, these results place it beneath the Southern Uplands, unless it is masked by the surface conductor in the Northumberland Basin

    Nitrate fluctuations at the water table: implications for recharge processes and solute transport in the Chalk aquifer

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    This study investigates fluctuations in nitrate concentration at the water table to improve understanding of unsaturated zone processes in the Chalk aquifer. Sampling was conducted using a novel multi-level sampler during periods of water table rise over 5 years at a vertical resolution of 0.05 m. Nitrate concentration increased as the water table seasonally recovered, with similar inter-annual trends with depth. The rising water table activated horizontal fractures facilitating the delivery of water elevated by up to 10 mg/l of nitrate with respect to the adjacent groundwater below. These fractures are considered to activate via piston displacement of water from the adjoining matrix. Hydrograph analysis identified 16 events which significantly perturbed the water table within 24–48 h of rainfall. Consistent nitrate concentrations indicate recharge through persistent fracture flow from the surface was not generally the primary driver of the rapid water table response during these events. Instead, the response was attributed to the piston displacement of porewater immediately above the water table. However, a single event in November 2012 delivered relatively dilute recharge indicating rapid persistent fracture flow following rainfall was possible to a depth of 14–15 m. Decreases in porewater nitrate concentration around fracture horizons and the dilution of many groundwater samples with respect to porewaters indicate a fresher source of water at depth. This was considered most likely to be a result of near surface water bypassing the matrix because of widespread mineralization on fracture surfaces, which retard water and solute exchange. Therefore, persistent fracture flow maybe considered a frequent process, operating independently of the matrix, and is not necessarily event driven

    The Learning Styles educational neuromyth:Lack of agreement between teachers’ judgments, self-assessment, and students’ intelligence

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    Learning styles (LS) have dominated educational practice since their popularization in the 1970s. Studies have shown that they are accepted by more than 90% of teachers worldwide. However, LS have also received extensive criticism from researchers and academics, due to the poor theoretical justification of the theory, their problematic measurement, and the lack of systematic studies supporting them. The present study tested the hypothesis that teachers' and students' assessment of preferred LS should correspond. Moreover, it tested whether teachers' judgment of LS is driven by the students' IQ. Both questions were studied for the first time in a systematic fashion within LS research in primary school pupils. Fifth and sixth grade pupils (n = 199) were asked to self-assess their preferred LS, while their teachers were asked to provide their own assessment on individual pupils' LS. No relationship was found between pupils' self-assessment and teachers' assessment, suggesting that teachers cannot assess the LS of their students accurately. Moreover, students' intelligence was not found to drive teachers' assessment of their LS. This study adds to the body of evidence that is skeptical of the adoption of LS in mainstream education

    Long-acting beta2-agonists for chronic obstructive pulmonary disease.

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    BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a respiratory disease that causes progressive symptoms of breathlessness, cough and mucus build-up. It is the fourth or fifth most common cause of death worldwide and is associated with significant healthcare costs.Inhaled long-acting beta2-agonists (LABAs) are widely prescribed to manage the symptoms of COPD when short-acting agents alone are no longer sufficient. Twice-daily treatment with an inhaled LABA is aimed at relieving symptoms, improving exercise tolerance and quality of life, slowing decline and even improving lung function and preventing and treating exacerbations. OBJECTIVES: To assess the effects of twice-daily long-acting beta2-agonists compared with placebo for patients with COPD on the basis of clinically important endpoints, primarily quality of life and COPD exacerbations. SEARCH METHODS: We searched the Cochrane Airways Group trials register, ClinicalTrials.gov and manufacturers' websites in June 2013. SELECTION CRITERIA: Parallel, randomised controlled trials (RCTs) recruiting populations of patients with chronic obstructive pulmonary disease. Studies were required to be at least 12 weeks in duration and designed to assess the safety and efficacy of a long-acting beta2-agonist against placebo. DATA COLLECTION AND ANALYSIS: Data and characteristics were extracted independently by two review authors, and each study was assessed for potential sources of bias. Data for all outcomes were pooled and subgrouped by LABA agent (formoterol 12 μg, formoterol 24 μg and salmeterol 50 μg) and then were separately analysed by LABA agent and subgrouped by trial duration. Sensitivity analyses were conducted for the proportion of participants taking inhaled corticosteroids and for studies with high or uneven rates of attrition. MAIN RESULTS: Twenty-six RCTs met the inclusion criteria, randomly assigning 14,939 people with COPD to receive twice-daily LABA or placebo. Study duration ranged from three months to three years; the median duration was six months. Participants were more often male with moderate to severe symptoms at randomisation; mean forced expiratory volume in 1 second (FEV1) was between 33% and 55% predicted normal in the studies, and mean St George's Respiratory Questionnaire score (SGRQ) ranged from 44 to 55 when reported.Moderate-quality evidence showed that LABA treatment improved quality of life on the SGRQ (mean difference (MD) -2.32, 95% confidence interval (CI) -3.09 to -1.54; I(2) = 50%; 17 trials including 11,397 people) and reduced the number of exacerbations requiring hospitalisation (odds ratio (OR) 0.73, 95% CI 0.56 to 0.95; I(2) = 10%; seven trials including 3804 people). In absolute terms, 18 fewer people per 1000 were hospitalised as the result of an exacerbation while receiving LABA therapy over a weighted mean of 7 months (95% CI 3 to 31 fewer). Scores were also improved on the Chronic Respiratory Disease Questionnaire (CRQ), and more people receiving LABA treatment showed clinically important improvement of at least four points on the SGRQ.The number of people who had exacerbations requiring a course of oral steroids or antibiotics was also lower among those taking LABA (52 fewer per 1000 treated over 8 months; 95% CI 24 to 78 fewer, moderate quality evidence).Mortality was low, and combined findings of all studies showed that LABA therapy did not significantly affect mortality (OR 0.90, 95% CI 0.75 to 1.08; I(2) = 21%; 23 trials including 14,079 people, moderate quality evidence). LABA therapy did not affect the rate of serious adverse events (OR 0.97, 95% CI 0.83 to 1.14; I(2) = 34%, moderate quality evidence), although there was significant unexplained heterogeneity, especially between the two formoterol doses.LABA therapy improved predose FEV1 by 73 mL more than placebo (95% CI 48 to 98; I(2) = 71%, low quality evidence), and people were more likely to withdraw from placebo than from LABA therapy (OR 0.74, 95% CI 0.69 to 0.80; I(2) = 0%). Higher rates of withdrawal in the placebo arm may reduce our confidence in some results, but the disparity is more likely to reduce the magnitude of difference between LABA and placebo than inflate the true effect; removing studies at highest risk of bias on the basis of high and unbalanced attrition did not change conclusions for the primary outcomes. AUTHORS' CONCLUSIONS: Moderate-quality evidence from 26 studies showed that inhaled long-acting beta2-agonists are effective over the medium and long term for patients with moderate to severe COPD. Their use is associated with improved quality of life and reduced exacerbations, including those requiring hospitalisation. Overall, findings showed that inhaled LABAs did not significantly reduce mortality or serious adverse events
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